Service schematic in PDF form for the K72JK notebook, a model designation in the K72 family. The file name lists no mainboard revision, so compare the title block inside with the version silk-screened on the PCB before trusting component values. Technicians use such diagrams to follow power rails from the charger and PWM controllers to the CPU, chipset and GPU, find test points, and track down shorts on a dead board. At about 2 MB it opens in any ordinary PDF viewer and can be searched by net name.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @alischematics. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.